CENTENNIAL, Colo. (AP) — Colorado’s governor asked the nation Sunday for prayers for the 17-year-old girl who was critically wounded by a classmate at her suburban Denver high school.

Gov. John Hickenlooper also credited security procedures adopted after the 1999 massacre at nearby Columbine High School for helping put a quick end to the Arapahoe High School shooting by Karl Pierson, an 18-year-old student who shot Claire Davis at point-blank range before killing himself.

“We all have to keep Claire in our thoughts and prayers,” he told CBS’ “Face the Nation.” Davis is hospitalized at Littleton Adventist Hospital.

Davis is in critical condition and stable, but she is in a coma, her family said in a statement issued on the hospital’s Facebook page Sunday.

“The first responders got Claire to the right place, at the right time,” the family said. They also praised the care she was receiving and expressed thanks for the outpouring of prayers and support.

About 500 classmates held a candlelight vigil Saturday for Davis, who was sitting with a friend near the school library when she was shot in the head. Arapahoe County Sheriff Grayson Robinson has said investigators think she was shot at random by Pierson, who had gone into the school looking for a teacher with whom he had a dispute.

Pierson may have been nursing a grudge against the teacher — a librarian and head of the school debate team — since September. Pierson was on the team and had been disciplined by the librarian for reasons yet to be disclosed, the sheriff said. He said Pierson threatened that teacher in September and came to the school Friday intending to harm him and inflict numerous other casualties.

Pierson excelled at speech and debate and was passionate about the team, friends said. They described him as a smart student who apparently didn’t shirk from confrontations in class.

“He’s a funny kid. He’s smart. He’s in the Eagle Scouts, a very intelligent kid. Did not like being wrong,” said August Clary, who was a friend of Pierson. “If you’re arguing with him, it’s going to be, that’s a feat if you win an argument against him.”

“He would not be afraid to tell someone how he feels,” said Zach Runberg, 18, a senior in Pierson’s English class.

Pierson legally bought a shotgun on Dec. 6 at a local store, and he purchased ammunition the morning of the shootings. He managed to ignite a Molotov cocktail inside the school library before he killed himself as a fast-acting school security officer, a deputy sheriff, closed in, Robinson said.

That officer’s aggressive response prevented more casualties, Robinson said. It’s a tactic adopted nationwide after Columbine, in which first responders cordoned off the school before pursuing two student gunmen inside. The two killed 12 students and a teacher before killing themselves.

“It’s nice to see how well the system worked. It’s a remarkable improvement from before. This could have been much, much worse,” Hickenlooper said.

After the Aurora, Colo., theater shootings and the Newtown, Conn., school shootings, Colorado’s Democrat-led legislature this year implemented gun control measures that limited the size of ammunition magazines and instituted universal background checks. Colorado also appropriated more than $20 million for mental health hotlines and local crisis centers.

The measures were intended to address violence associated with so-called assault rifles, not shotguns that are widely owned for hunting and sport.

Hickenlooper acknowledged the latest shooting raised again questions about guns and violence. But he noted that Pierson “didn’t seem to exhibit any signs of mental illness,” and he cautioned that the investigation was in its early stages.

“Everyone in Colorado is asking the same questions,” the governor said. “On the one hand there is a deeply held conviction for the freedoms laid out in the Second Amendment, but also a very, very strong conviction about the safety of children and the safety of the community.”

Friday’s shooting, he said, “defies any explanation, and you know we are searching for some pattern.”